The Bosch Rotak 40 Ergoflex is a four wheeledrotary electric push mower with a rear roller. It’s the largest of the the Bosch Ergoflex family and, with it’s 40 cm (16 inch) cutting width, is designed for small to medium sized gardens. Bosch make much of the Ergoflex system which allows you to change hand positions as you’re cutting, but is it a one trick pony ?

The Bosch Rotak 40 Ergoflex arrived in a fairly large box and needed to be assembled, a task that we found relatively easy despite the lack of written instructions. Within 20 minutes or so, by following the diagrams we had it done although we did struggle a little with the self-tapping screws that hold the handle to the base.

It seems that we are not alone – a quick search on Google will show that others have had problems getting tightening these screws as well. Some people resort to drilling out the holes so that they can fit the screws more easily but this will not only void your 2 year warranty but will also mean that the handle is less secure and prone to coming off when in use.

Instead of drilling out the holes we swapped the electric screwdriver that we had been using in favour of a large flat headed screwdriver and this gave us enough torque to be able to do the screws up fully without voiding the warranty. It’s worth noting that, at this point, we did need another person to hold the handle steady whilst we did the screws up.

The only other item that needed to be assembled was the grass box and the two halves of this went together quickly and easily. All in all, assembly took less than twenty minutes.

What you’re left with is a very sturdy yet light weight electric mower with a rear roller with a lots of nice design features.

First up is the handle which can be gripped horizontally or vertical to avoid wrist strain and which features four control buttons (two lots of two identical sets) so that you can change hand positions without stopping the motor. And the extra control buttons provide an extra benefit: due to their positions this mower is perfect for lefthanded folks as well as right handers.

The body of the mower has two well placed carrying handles including one on top which make picking up and moving the mower simple and easy.

Adjustment of the cutting height between 20 mm and 70 mm over 10 steps is simple and easy thanks to the single centrally located adjustment lever.

Another feature that we like is that the cable plugs in to the mower so that should the cable get damaged it can be easily replaced. It also makes the mower easier to store as you don’t need a big bundle of cable hanging from it. And at 15 metres in length the cable is long enough for most small to medium sized gardens although you can always use an extension lead if you need to.

An interesting feature are the two red combs that sit just behind the front wheels and which are meant to pull the grass under the cutting deck so that it can cut right up to the edge. The theory is that this will save you time by removing the need to strim after you’ve cut the lawn.

But do they work ?

Oh yes ! We can honestly say that this is one of the best electric mowers that we have tested with an exceptional cut. The combs really do work and allows the mower to cut right up to the edge of lawn. Due to the inset front wheels it’s possible to get right up to the bottom of walls and fences too. Our test lawn normally needs the edges to be strimmed but the Bosch Rotak 40 Ergoflex meant that we only had 10% of the normal strimming left to do.

And because this it sits lower to the ground than a hover mower it provides a neater finish too, collecting all of the grass cuttings and leaving a nice striped finish even when cutting longer grass. We were pleasantly surprised by how well it coped with long wet grass thanks to its powerful 1700 Watt motor which was surprisingly quiet.

The 50 litre grass box worked well and packed the cuttings in well so that we were probbaly spared a few trips to the compost heap to empty but when we did the well positioned handles made the removal, emptying and refitting of the grass box a doddle.

The overall light weight of the mower (it weighs 12 kg) mean that it was easy to manoeuvre and the extra hand positions also made it comfortable to use over long periods.

All in all this is an exceptional mower and there’s not one thing that we can find to criticise. If you’re in the market for a electric push mower with a roller that leaves an exceptionally fine finish then look no further. Throw in a two year warranty and it’s a no brainer ! Buy it!

Bosch also make a smaller version which impressed us just as much as the big version called the Bosch Rotak 34 Ergoflex which is identical in every respect other than being slightly smaller (it’s got a 34 cm cutting width and is a kilogram or so lighter) and which performs just as well.